Separation of Co(II) Over Ni(II) from Chloride Leached Solution of Spent Li-Ion Batteries Using Cyphos IL104

Abstract

The hydrometallurgical separation of cobalt and nickel was achieved from HCl leached solution of spent Li-ion batteries, while applying Cyphos IL104 as a potential extractant. Cobalt extraction significantly increases with increasing Cyphos IL104 and Cl− ion concentrations, and equilibrium pH (pHeq). Under the optimized condition of 0.8 mol·L−1 Cyphos IL104, 3.0 mol·L−1 Cl− ions, pHeq value 5.0, and O/A ratio of 2/3 could extract >99% Co with only 3% Ni into the organic phase. The back-extraction of cobalt performed with 2.0 mol·L−1 H2SO4 solution yielded 99.95% stripping efficiency and was crystallized to obtain high-pure CoSO4.xH2O crystals.